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You searched for: subject:"state estimation"
[texts]State Estimation of Power System with Interline Power Flow Controller
Now-a-days Flexible A.C. Transmission System (FACTS) controllers are incorporated into the power system network to control the power flow andenhance system stability. Traditional state estimation methods without integrating FACTS devices will not be suitable for power systems embedded with FACTS controller. Based on the conventional power system state estimation model, a new method is proposed wherein an IPFC based power injection model is incorporated in the state estimation algorithm...
Keywords: IPFC; Power Injection model; FACTS; State Estimation; WLS
Downloads: 51
[texts]Power System State Estimation - A Review
The aim of this article is to provide a comprehensivesurvey on power system state estimation techniques. Thealgorithms used for finding the system states under both staticand dynamic state estimations are discussed in brief. Theauthors are opinion that the scope of pursuing research in thearea of state estimation with PMU and SCADA measurementsis the state of the art and timely.
Keywords: State Estimation; LAV; WLS; Kalman; Synchronized phasor measurements; PMU
Downloads: 16
[texts]Optimal Location of PMUs for Complete Observability of Power System Sub Network
Improvements in power system control and protection is achieved by utilizing real time synchronized phasor measurements. The trend in recent years is the steady increase of Phasor Measurement Unit (PMU) installations worldwide for various applications those targeted for State Estimation enhancement. This paper solves the optimal placement of phasor measurement units for complete observability using Integer LinearProgramming (ILP) solution methodology.ILP is used to determine the minimum optimal ...
Keywords: Integer Linear Programming (ILP); PMU placement; State Estimation; Complete Observability
Downloads: 191
[texts]State Estimation of Power System with Interline Power Flow Controller
Now-a-days Flexible A.C. Transmission System (FACTS) controllers are incorporated into the power system network to control the power flow andenhance system stability. Traditional state estimation methods without integrating FACTS devices will not be suitable for power systems embedded with FACTS controller. Based on the conventional power system state estimation model, a new method is proposed wherein anIPFC based power injection model is incorporated in the state estimation algorithm...
Keywords: IPFC; Power Injection model; FACTS; State Estimation; WLS
Downloads: 129
[texts]Portable digital pressure indicator for calibrating magnetic tape recorders - Mccormick, Royce F.
The design of a portable Digital Pressure Indicator (DPI) to be used for calibrating the pressure systems on Langley's magnetic tape recorders is described. High-speed magnetic tape recorders require pressure (0 to 20 psig) for providing an air cushion across the tape guides and a slight vacuum (30 inch H2O) for maintaining the proper number of tape loops in the advance and feed chamber. The DPI is a hand-held device that can be quickly coupled to a magnetic tape recorder and includes a two-posi...
Keywords: ISOTROPIC MEDIA; YIELD STRENGTH; STATE ESTIMATION; STRAIN HARDENING; THERMODYNAMICS; VISCOPLASTICITY; DRAG; EQUATIONS OF STATE; KINEMATICS; RECOVERABILITY
Downloads: 67
[texts]Neural Dynamics Underlying Event-Related Potentials - Shah, Ankoor S.
There are two opposing hypotheses about the brain mechanisms underlying sensory event-related potentials (ERPs). One holds that sensory ERPs are generated by phase resetting of ongoing electroencephalographic (EEG) activity, and the other that they result from signal averaging of stimulus-evoked neural responses. We tested several contrasting predictions of these hypotheses by direct intracortical analysis of neural activity in monkeys...
Keywords: MICROWAVE ANISOTROPY PROBE; ALGORITHMS; ANGULAR VELOCITY; ATTITUDE (INCLINATION); STATE ESTIMATION; SPACECRAFT INSTRUMENTS; GYROSCOPES; STAR TRACKERS
Downloads: 84
[texts]Portable Instrument to Measure CDOM Light Absorption in Aquatic Systems: WPI Success Story - NON
World Precision Instruments, Inc. (WPI), of Sarasota, FL, in collaboration with NASA's John C. Stennis Space Center, has developed an innovative instrument to accurately measure Colored Dissolved Organic Matter (CDOM) absorption in the field. This successful collaboration has culminated in an exciting new device, called the UltraPath, now commercially available through WPI. Traditional methods of measuring absorption of dissolved materials require special handling and storage prior to measuremen...
Keywords: BAYES THEOREM; KALMAN FILTERS; NOISE INTENSITY; MONTE CARLO METHOD; ACOUSTIC SIMULATION; FAULT DETECTION; STATE ESTIMATION; SELECTION
Downloads: 118
[texts]Effect of Phasor Measurement Unit (PMU) on the Network Estimated Variables
The classical method of power measurement of asystem are iterative and bulky in nature. The new technique of measurement for bus voltage, bus current and power flow is a Phasor Measurement Unit. The classical technique and PMUs are combined with full weighted least square state estimator method of measurement will improves the accuracy of the measurement. In this paper, the method of combining Full weighted least square state estimation method and classical method incorporation with PMU for meas...
Keywords: classical method; phasor measurement units (PMUs); state estimation; full weighted least square (WLS) state
Downloads: 132
[texts]Traffic State Estimation and Prediction under Heterogeneous Traffic Conditions
The recent economic growth in developing countries like India has resulted in an intense increase of vehicle ownership and use, as witnessed by severe traffic congestion and bottlenecks during peak hours in most of the metropolitan cities. Intelligent Transportation Systems (ITS) aim to reduce traffic congestion by adopting various strategies such as providing pre-trip and en-route traffic information thereby reducing demand, adaptive signal control for area wideoptimization of traffic flow, etc...
Keywords: Intelligent Transportation System; traffic state estimation; macroscopic traffic modeling; heterogeneous traffic condition
Downloads: 123
[texts]Traffic State Estimation and Prediction under Heterogeneous Traffic Conditions
The recent economic growth in developing countrieslike India has resulted in an intense increase of vehicleownership and use, as witnessed by severe traffic congestionand bottlenecks during peak hours in most of the metropolitancities. Intelligent Transportation Systems (ITS) aim to reducetraffic congestion by adopting various strategies such asproviding pre-trip and en-route traffic information therebyreducing demand, adaptive signal control for area wideoptimization of traffic flow, etc...
Keywords: Intelligent Transportation System; traffic state estimation; macroscopic traffic modeling; heterogeneous traffic condition
Downloads: 6
[texts]The problem of resonance in technology usage - Sayani, H. H.
Various information system tools and techniques are analyzed. A case study is presented which draws together the issues raised in three distinct cases. This case study shows a typical progression from the selection of an analysis methodology, to the adoption of an automated tool for specification and documentation, and the difficulty of fitting these into an existing life cycle development methodology.
Keywords: FLIGHT CHARACTERISTICS; HELICOPTER CONTROL; ROTARY WING AIRCRAFT; SYSTEMS ENGINEERING; COMPUTER PROGRAMS; HELICOPTER PERFORMANCE; MATHEMATICAL MODELS; STATE ESTIMATION
Downloads: 61
[texts]Duality between surface coupled interfacial for electrically charged and self gravitating drops - Zahn, M
No Abstract Available
Keywords: COMPUTERIZED SIMULATION; SPACE RENDEZVOUS; SPACECRAFT DOCKING; VIDEO EQUIPMENT; AXES OF ROTATION; COMPUTER PROGRAMS; SATELLITE ATTITUDE CONTROL; SPACECRAFT STABILITY; STATE ESTIMATION
Downloads: 54
[texts]A Systematic Global Mapping of the Radiation Field at Aviation Altitudes - Stassinopoulos, E. G.
This paper presents early results from aircraft measurements made by a Low-LET Radiation Spectrometer (LoLRS), as part of a long-range effort to study the complex dynamics of the atmospheric radiation field. For this purpose, a comprehensive data base is being generated to enable a multivariable global mapping (and eventually modeling) of doses and Linear-Energy-Transfer (LET) spectra at aviation altitudes...
Keywords: ALGORITHMS; DECISION THEORY; HEURISTIC METHODS; MARKOV PROCESSES; SYMBOLS; DYNAMIC PROGRAMMING; STATE ESTIMATION; CONVERGENCE; VERY LARGE SCALE INTEGRATION
Downloads: 79
[texts]IMAT (Integrated Multidisciplinary Analysis Tool) user's guide for the VAX/VMS computer - NON
The Integrated Multidisciplinary Analysis Tool (IMAT) is a computer software system for the VAX/VMS computer developed at the Langley Research Center. IMAT provides researchers and analysts with an efficient capability to analyze satellite control systems influenced by structural dynamics. Using a menu-driven executive system, IMAT leads the user through the program options. IMAT links a relational database manager to commercial and in-house structural and controls analysis codes...
Keywords: AERODYNAMIC DRAG; PREDICTIONS; STATE ESTIMATION; COMPUTER TECHNIQUES; ORBIT CALCULATION; ORBIT PERTURBATION; ZONAL HARMONICS; ALGORITHMS; MICROCOMPUTERS; ORBIT DECAY; POSITION (LOCATION)
Downloads: 135
[texts]Tethers in space handbook, second edition - NON
The Tethers in Space Handbook, Second Edition represents an update to the initial volume issued in September 1986. As originally intended, this handbook is designed to serve as a reference manual for policy makers, program managers, educators, engineers, and scientists alike. It contains information for the uninitiated, providing insight into the fundamental behavior of tethers in space. For those familiar with space tethers, it includes a summary of past and ongoing studies and programs, a comp...
Keywords: ATTITUDE INDICATORS; STATE ESTIMATION; FLIGHT CONTROL; GLOBAL POSITIONING SYSTEM; INTERFEROMETRY; NAVIGATION INSTRUMENTS; RECEIVERS; ALGORITHMS; DC 3 AIRCRAFT; FLIGHT TESTS
Downloads: 475
[texts]Investigation of Dynamic Oxygen Adsorption in Molten Solder Jetting Technology - Megaridis, Constantine M.
Surface tension forces play a critical role in fluid dynamic phenomena that are important in materials processing. The surface tension of liquid metals has been shown to be very susceptible to small amounts of adsorbed oxygen. Consequently, the kinetics of oxygen adsorption can influence the capillary breakup of liquid-metal jets targeted for use in electronics assembly applications, where low-melting-point metals (such as tin-containing solders) are utilized as an attachment material for mounti...
Keywords: DECISION SUPPORT SYSTEMS; TELEMETRY; STATE ESTIMATION; WARNING SYSTEMS; COMPUTER PROGRAMS; FAULT DETECTION; NUMERICAL CONTROL; DATA SYSTEMS; INTERNATIONAL SPACE STATION; RISK; FLIGHT CONTROL
Downloads: 131
[texts]Densities and abundances of hot cometary ions in the coma of P/Halley - Neugebauer, M.
On its flight by P/Halley, the Giotto spacecraft carried a High Energy Range Spectrometer (HERS) for measuring the properties of cometary ions picked up by the solar wind in the nearly collisionless regions of the coma. Preliminary estimates of the ion densities observed by HERS were reevaluated and extended; density profiles along the Giotto trajectory are presented for 13 values of ion mass/charge...
Keywords: CIRCULAR ORBITS; TRAJECTORY PLANNING; SPACECRAFT GUIDANCE; STATE ESTIMATION; ELLIPTICAL ORBITS; ERROR ANALYSIS; MONTE CARLO METHOD; RENDEZVOUS SPACECRAFT; ROBUSTNESS (MATHEMATICS); SPACECRAFT MANEUVERS; SPACECRAFT ORBITS; SPACECRAFT TRAJECTORIES
Downloads: 75
[texts]Precise timing correlation in telemetry recording and processing systems - Pickett, R. B.
Independent PCM telemetry data signals received from missiles must be correlated to within or - 100 microseconds for comparison with radar data. Tests have been conducted to determine RF antenna receiving system delays; delays associated with wideband analog tape recorders used in the recording, dubbing and repdocuing processes; and uncertainties associated with computer processed time tag data. Several methods used in the recording of timing are evaluated...
Keywords: LOW THRUST PROPULSION; ORBITAL POSITION ESTIMATION; STATE ESTIMATION; STOCHASTIC PROCESSES; SPACE NAVIGATION; SPACECRAFT GUIDANCE; EQUATIONS OF MOTION; EQUATIONS OF STATE; FEEDBACK; FLIGHT SIMULATION; KALMAN FILTERS; MATHEMATICAL MODELS
Downloads: 113
[texts]Fatigue damage in cross-ply titanium metal matrix composites containing center holes - Bakuckas, J. G., Jr.
The development of fatigue damage in (0/90) sub SCS-6/TI-15-3 laminates containing center holes was studied. Stress levels required for crack initiation in the matrix were predicted using an effective strain parameter and compared to experimental results. Damage progression was monitored at various stages of fatigue loading. In general, a saturated state of damage consisting of matrix cracks and fiber matrix debonding was obtained which reduced the composite modulus...
Keywords: AIR NAVIGATION; FAULTS; LEAST SQUARES METHOD; NAVIGATION AIDS; RECEIVERS; ALGORITHMS; FAULT DETECTION; FAULT TOLERANCE; POSITION ERRORS; STATE ESTIMATION; STATISTICAL ANALYSIS; AUTONOMY; ERROR ANALYSIS
Downloads: 143
[texts]Grasping objects autonomously in simulated KC-135 zero-g - Norsworthy, Robert S
The KC-135 aircraft was chosen for simulated zero gravity testing of the Extravehicular Activity Helper/retriever (EVAHR). A software simulation of the EVAHR hardware, KC-135 flight dynamics, collision detection and grasp inpact dynamics has been developed to integrate and test the EVAHR software prior to flight testing on the KC-135. The EVAHR software will perform target pose estimation, tracking, and motion estimation for rigid, freely rotating, polyhedral objects...
Keywords: ARTIFICIAL INTELLIGENCE; STATE ESTIMATION; SURFACE NAVIGATION; COMPUTER VISION; DYNAMIC MODELS; REAL TIME OPERATION; VISUAL CONTROL; AIRCRAFT LANDING; ARCHITECTURE (COMPUTERS); AUTONOMY; SPACECRAFT DOCKING
Downloads: 88
[texts]Shuttle Ground Operations Efficiencies/Technologies Study (SGOE/T). Volume 5: Technical Information Sheets (TIS) - Scholz, A. L.
The Technology Information Sheet was assembled in database format during Phase I. This document was designed to provide a repository for information pertaining to 144 Operations and Maintenance Instructions (OMI) controlled operations in the Orbiter Processing Facility (OPF), Vehicle Assembly Building (VAB), and PAD. It provides a way to accumulate information about required crew sizes, operations task time duration (serial and/or parallel), special Ground Support Equipment (GSE)...
Keywords: ALGORITHMS; LINEAR SYSTEMS; MATRICES (MATHEMATICS); STOCHASTIC PROCESSES; CONTROLLABILITY; DYNAMICAL SYSTEMS; FEEDBACK CONTROL; KALMAN FILTERS; STATE ESTIMATION; STATE VECTORS; COST REDUCTION; COVARIANCE
Downloads: 162
[texts]Effect of grain size on the high temperature properties of B2 aluminides - Whittenberger, J. Danie
Measurements of the slow plastic flow behavior of cobalt, iron and nickel B2 crystal structure aluminides were conducted on materials fabricated by metallurical techniques. Due to this processing, the aluminides invariably had small equiaxed grains, ranging in size from about 3 to 60 microns in diameter. Grain size was dependent on the extrusion temperature used for powder consolidation, and it proved to be remarkably stable at elevated temperatures...
Keywords: APPROXIMATION; FEEDBACK CONTROL; LINEAR QUADRATIC REGULATOR; STATE ESTIMATION; COMPENSATORS; CONTROL SYSTEMS DESIGN; FLEXIBLE BODIES; LINEAR QUADRATIC GAUSSIAN CONTROL; RICCATI EQUATION; CONVERGENCE; DYNAMIC CONTROL; ESTIMATORS
Downloads: 48
[texts]The spatial resolving power of earth resources satellites: A review - Townshend, J. R. G
The significance of spatial resolving power on the utility of current and future Earth resources satellites is critically discussed and the relative merits of different approaches in defining and estimating spatial resolution are outlined. It is shown that choice of a particular measure of spatial resolution depends strongly on the particular needs of the user. Several experiments have simulated the capabilities of future satellite systems by degradation of aircraft images...
Keywords: AERODYNAMIC CHARACTERISTICS; MAXIMUM LIKELIHOOD ESTIMATES; ROTOR AERODYNAMICS; MATHEMATICAL MODELS; PARAMETER IDENTIFICATION; ROTARY WING AIRCRAFT; STATE ESTIMATION; AEROELASTICITY; DEGREES OF FREEDOM; HELICOPTER DESIGN; KALMAN FILTERS
Downloads: 96
[texts]Automated Rendezvous and Docking: 1994-2004 - NON
This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic includes technologies for human exploration and robotic sample return missions. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.
Keywords: COMPUTER SYSTEMS PROGRAMS; PROGRAMMING LANGUAGES; LINEAR EQUATIONS; ARTIFICIAL INTELLIGENCE; AUTOMATIC CONTROL; SYSTEMS ENGINEERING; APPLICATIONS PROGRAMS (COMPUTERS); SPECIFICATIONS; ALGORITHMS; STATE ESTIMATION; DATA PROCESSING
Downloads: 141
[texts]7. Eng Modified H. Nagaraja Udupa - H. Nagaraja Udupa & H. Ravishankar Kamath
Estimating the state of the power system in Real time is a challenging task, mainly because, solving the non-linear  large power system equations by iterative solution comsumes huge computational time and memory. Online Energy Management System (EMS) these state estimators need to  Estimate the state of the system at very short intervals.  Conventional methods like Newton-Raphson is not suitable for such real time application...
Keywords: SE-State Estimation; WLS-Weight Least Square; RTU-Remote Terminal Unit; NR-Newton Rapson; AI-Artificial Intelligence; Node Area-A Node along with its Connected Node is Referred as Node Area
Downloads: 4
[texts]Solar influences on global change - NON
Monitoring of the Sun and the Earth has yielded new knowledge essential to this debate. There is now no doubt that the total radiative energy from the Sun that heats the Earth's surface changes over decadal time scales as a consequence of solar activity. Observations indicate as well that changes in ultraviolet radiation and energetic particles from the Sun, also connected with the solar activity, modulate the layer of ozone that protects the biosphere from the solar ultraviolet radiation...
Keywords: AUTONOMY; TRAJECTORY CONTROL; AEROSPACE ENVIRONMENTS; C-135 AIRCRAFT; PARABOLIC FLIGHT; SPACE STATIONS; STATE ESTIMATION; WEIGHTLESSNESS SIMULATION; COMPUTER VISION; MICROGRAVITY; OPTICAL TRACKING; ORBITAL ASSEMBLY; ORBITAL SERVICING; REAL TIME OPERATION; ROBOT CONTROL; ROBOTS
Downloads: 185
[movies]MIT 6.832 Underactuated Robotics, Spring 2009 - MIT OpenCourseWare
Instructor: Russell Tedrake Robots today move far too conservatively, using control systems that attempt to maintain full control authority at all times. Humans and animals move much more aggressively by routinely executing motions which involve a loss of instantaneous control authority. Controlling nonlinear systems without complete control authority requires methods that can reason about and exploit the natural dynamics of our machines...
Keywords: underactuated robotics; actuated systems; nonlinear dynamics; simple pendulum; optimal control; double integrator; quadratic regulator; Hamilton-Jacobi-Bellman sufficiency; minimum time control; acrobot; cart-pole; partial feedback linearization; energy shaping; policy search; open-loop optimal control; trajectory stabilization; iterative linear quadratic regulator; differential dynamic programming; walking models; rimless wheel; compass gait; kneed compass gait; feedback control; running models; spring-loaded inverted pendulum; Raibert hoppers; motion planning; randomized motion planning; rapidly-exploring randomized trees; probabilistic road maps; feedback motion planning; planning with funnels; linear quadratic regulator; function approximation; state distribution dynamics; state estimation; stochastic optimal control; aircraft; swimming; flapping flight; randomized policy gradient; model-free value methods; temporarl difference learning; Q-learning; actor-critic methods
Downloads: 18,532
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